Double blow header



y 1966 YOSHIKAZU SAKAMURA 3,260,096

DOUBLE BLOW HEADER Filed Oct. 4, 1963 2 Sheets-Sheet 1 IN VEuTo/l: fa, kmmm 81-. ND TE M NOLTE AU T'WS y 12, 1966 YOSHIKAZU SAKAMURA 3,260,096

DOUBLE BLOW HEADER Filed Oct. 4, 1963 2 Sheets-Sheet 2 3 93 ,W v A 93 83 /8 United States Patent 1 Claim. 0172-391 This invention relates to double blow headers in which a pair of punches carried by a shiftable punch carrier are alternately positioned in alignment with a work piece in the die, and particularly to stop means for the punch carrier in double blow headers of such kind.

Double blow headers have a bed frame carrying a reciprocating header gate, driven by a crankshaft on the frame, which gate carries a shaftable punch carrier operated at half crankshaft speed, so that on one advance stroke of the gate a first punch engages a blank held by transfer fingers in alignment with a die, pushes the blank into the die and upsets the blank, and on the next advance stroke the punch carrier is shifted and so presents a second punch to the work now recessed in the same die. After the second blow the blank is ejected from the die by knockouts and the transfer fingers bring a new blank into a projected position in front of the die. In order to move the punch carrier mounted on the gate so as to shift the carrier between its two alternative positions at the correct time, and in order to positively maintain the carrier in its operating position during the final portion of each advance stroke of the gate, the half speed cam shaft is provided with a punch carrier drive cam which has a minor dwell arc and a major dwell are joined by lift portions. The shifting stroke of the punch carrier depends on the shape of the drive cam. With such a double-dwell, positive motion,

punch carrier drive cam as above, it is difficult to adjust the shifting stroke of the punch carrier for exact alignment of the punches with the work piece or die.

Some attempts have been made for the provision of positive steps for the pun-ch carrier at the two alternative work positions. The positive stops are mounted on the gate to maintain the punch carrier at its two extreme positions. The main crankshaft turns continuously, as does the half speed cam shaft. This means that the gate having the stops is ever moving except at the very end of its stroke. The adjustment of the stops during operation is very diflicult, particularly at high speed operation.

The primary object of the invention is to provide a double blow header in which the shifting stroke at the punch carrier is adjustable at will.

Another object of the invention is to provide stop means for the punch carrier, the position of which is adjustable without difficulties whether under the rest position or during operation of the machine.

According to the invention, the above objects can be attained by the combination of positive stops for the punch carrier, which are adjustably positioned on the frame, with spring over-travel accommodation device which is inserted in the punch carrier drive means. The stops are adjustable even during operation of the machine because said stops are mounted on the fixed, stationary frame while the gate with punch carrier moves continuously. Any overtravel of the punch carrier which may occur is eliminated by spring device inserted in the punch carrier drive mechanism. The stop members according to the invention have the respective abutment surfaces extending in the direction of the stroke so that on the advance stroke of said gate the punch carrier moves along the abutment surface, whereby the carrier may be positively maintained in its exact operating position during each advance stroke of the gate, at least during the final portion thereof.

In the preferred embodiment of the invention, the two punches are carried by a punch carrier in such manner that their relative positions to the punch carrier can be minutely adjusted. This may be accomplished by pivotally carrying the punch holders by the punch carrier at eccentric positions with respect to the respective punches with operation of adjust and set screws.

The other objects and advantages of the invention will be apparent from the following detailed descriptions with reference to the drawing showing a preferred embodiment of the invention, in which:

FIG. 1 is a front view, partly in section and partly cut off, showing a double blow header embodying the invention;

FIG. 2 is a side elevational view taken along the line 22 of FIG. 1;

FIG. 3 is a cross section taken along line 33 of FIG. 1; and

FIG. 4 is a cross section taken along the line 44 of FIG. 1.

A preferred embodiment of the invention includes a main frame 11 which supports a carrying die 12 with an opening 13 for receiving a work piece 14 and suitable knockout means which may include a knockout pin 15 and a push rod 16, as well as in known double blow headers.

The gate 17 carrying the punches is slidably mounted in the frame 11 and incorporates a face plate or head 18 on which a slidable punch carrier 19 is supported. The punch carrier 19 has a pair of punch holders 20 and 21 holding the first and second punches 22 and 23, respectively. The two punches 22 and 23 are alternately positioned to the work piece 14 in the die 12.

There is a main crankshaft 24 that may be power driven by a belt and pulley arrangement (not shown) known in the art. The crankshaft 24 has a crank 25 that drives a connecting rod 26 which is in turn jointed to the gate 17. 27 is a crank pin for connecting the crank 25 to the connecting rod 26 and 28 is a pin for connecting the rod 26 to the gate 17. The gate 17 slides in guide Ways 29 in the frame 11 which receive guide flanges 30 extending laterally from the gate 17.

In the preferred embodiment of the invention, the mechanism for shifting the punch carrier 19 so that the two punches 22 and 23 may become alternately aligned with the work piece 14 in the die 12, is driven at half crank shaft speed. To this end, there is a driving pinion 31 keyed to the crank shaft 24 which meshes with a half speed gear 32 keyed to a cross shaft 33 which provides the drive means for shifting the punch carrier 19 between either of its two alternative work positions as will be now described.

To the cross shaft 33 is keyed a drive cam 34 having a minor dwell arc 34a and a major dwell arc 34b joined by lift portions 340 and 34d. The cross shaft 33 also pivotally supports a square slide block 35 along which a cam follower assembly generally indicated as 36 is slidable in the direction of its length. The member 36 is provided with a pair of rollers 37 and 38 which are spaced in the direction of the length of the member 36 from each other and engage with the cam 34 in such a manner that the cam 34 is held therebetween in the direction of a diameter of the shaft 33. 39 and 40 are rocker pins for pivotally carrying the rollers 37 and 38, respectively. The member 36 is formed with a fork-shaped end portion 41 which is connected Via another square slide block 42 to an arm 43 keyed to a pivot 44. The slide block 42 is held between a pair of parallel prongs 45 of the fork 41 and slidable along the direction thereof. 46 is a pin for pivotally connecting the slide block 42 to the arm 43. The slide block 42 is also connected in a spaced relation to a cross head 47 which is slidably carried by the fork prongs 45. The distance between the slide block 42 and the cross head 47 may be adjust- -13 able. This may be accomplished by connecting the cross head 47 to the slide block by means of screw-securing. 48 is a screw fixed on the slide block 42 and 49 indicates a pair of nuts maintaining the cross head 47 in position on the screw 48.

According to the invention, a spring overtravel accommodation device is inserted in the punch carrier drive mechanism. This may be carried out, by way of example, by connecting the cross head 47 via spring means to the member 36 so that usually the member 36 may be accompanied with the cross head 47 and the slide block 42, while resiliently accommodating certain slight motion of the cross head 47 with the slide block 42 when resisted. In the embodiment illustrated in the drawings, the cross head 47 is provided with a pair of columns 50 which extend in parallel with the prongs at their respective outsides and slidably through wing portions 51 formed at the prongs 45. Each column is provided in front and in the rear of the wing portion 51 with flanges 52 and 53 and partially compressed springs 54 and 55 are set between these two flanges 52 and 53 and the wing portion 51, respectively.

The pivot 44 of the arm 43 fixedly carries a swing arm which is connected by a connecting rod 61 to a punch carrier shifting crank 62 pivotally carried by a rocker pin 63. The connecting rod 61 may be connected to the arm 60 and crank 62 by means of ball joints 64 and 65, respectively. The crank 62 is incorporated with a link 66 which is in turn connected by a pin 67 to the punch carrier 19. The rocker pin 63 is fixedly supported by the gate head 18. The gate head 18 is provided with another rocker pin 68 which pivotally carries a link 69 connected by a pin 70 to the punch carrier 19. The link 69 is parallel to and of the same length as the link 66 so that the two links 66 and 69 cooperate with the member 19 to form a parallelogram linkwork.

The swing portion of the swing arm 60 gives reciprocating angle motion to the crank 62 which in turn gives a substantially lateral, reciprocating motion to the punch carrier 19 between two alternative work positions.

In order to maintain the punch carrier on the gate head in a closely abutment condition, a guide roller 71 is supported by the gate head 18 so as to slidably hold the projected top portion 72 of the punch carrier 19 between the roller 71 and the front face 73 of the gate head 18. 74 is a hanger for the roller 71, and 75 is a pin for pivotally carrying the roller 71.

The two blow header according to the invention, is provided with positive stops for the punch carrier in its two extreme positions. As best seen in FIGS. 2 and 3, mounted on the frame 11 is a left hand stop member 81 in such a manner that its position is adjustable in the direction perpendicular to the stroke of the gate 17, while its movement in the direction of the stroke of the gate 17 is prevented. The stop member 81 has a guide surface 82 extending in parallel with the direction of the stroke of the gate 17. 83 indicates a pair of adjust screws for setting up the relative position of the stop member 81 to the frame 11 and 84 indicates clamp screws for securing the stop member 81 to the frame 11. The corresponding right hand stop assembly includes a stop member 91 having a guide surface 92, adjust screws 93 and clamp screws 94.

The punch carrier 19 is provided at its opposite sides with certain members or portions and 95 which cooperate with the guide surfaces 82 and 92 of the stop members 81 and 91, respectively. Preferably, the members 85 and 95 are rollers pivotally carried by the punch carrier 19 at its opposite side end portions but they may be formed in slide blocks incorporated with the carrier 19. On the advance stroke of the gate 17, at least during the final portion thereof, the punch carrier 19 abuts alternatively against either of stop members 81 and 91 and is moved therealong, the member 85 or 95 being engaged with and rolled on the guide surface 82 or 92.

In the preferred embodiment of the invention, the punch holders 20 and 21 are pivotally mounted on the gate head 18 by means of stub shafts and 101, respectively, retained in place by their own set screws 102 and 103 extending from the respective top surfaces 106 and 107 of the holders 20 and 21. The stub shafts 102 and 103 are eccentrically positioned with respect to the punches 22 and 23 so that pivotal movement of the punch holders 20 and 21 about the stub shafts 102 and 103 result in minute adjustment of the respective relative positions of the punches 22 and 23 to the punch holder 19. A pair of adjust screws 104, for setting up the relative position of each punch holder 20, 21 to the punch carrier 19 are vertically arranged at the opposite sides with respect to the punch 22, 23 and engage the top surface 106, 107 of the punch holder 20, 21. These adjust screws 104 and 105 are supported by the punch carrier 19 by means of screw-threading. The arrangement of all the set screws 102, 103 and adjust screws 104 and 105 at the top side of the punch holders 20 and 21 is advantageous because of convenience for adjust operation.

To summarize the operation of the device briefly, as the crankshaft 24 advances and retracts the gate 17, the drive cam 34 is so timed that the punch carrier 19 is alternately shifted to one of its two work positions before the punches engage the work piece. The punch shifting operation is carried out in each retract stroke of the gate 17 during the time that the follower member 36 is driven by the lift portions 34c or 34d. Once this shifting has occurred the punch carrier 19 is maintained by either of stop members 81 and 91 in its operating position in each advance stroke of the gate 19, at least during the final portion thereof, while the follower members 36 rest on the dwell arcs 34a and 34b. The positions of the stop members 81 and 91 are adjustable without difficulties at any time during operation of the machine because the stop members 81 and 91 are mounted on the stationary frame 11.

Although the foregoing description is necessarily of a detailed character, in order that the invention may be completely set forth, it is to be understood that modification may be made without departing from the scope or spirit of the invention as herein claimed.

What I claim is:

In a double blow header including a stationary frame, a gate movably mounted on said frame, a main crankshaft, means between said main crankshaft and gate for reciprocating the gate, a half speed cam shaft driven by said main crankshaft, a punch carrier shiftably mounted on said gate for motion between two alternative work positions laterally spaced from each other, and a punch carrier drive means driven by said half speed cam shaft; the combination of positive stop means for said punch carrier at said alternative work positions, which comprises a pair of stop blocks against which said punch carrier alternatively abuts, each of said stop blocks being.

adjustably positioned on said stationary frame and having an abutment surface extending in the direction of I the stroke of said gate so that on the advance stroke of said gate said punch carrier moves along said abutment surface, with a spring over-travel accommodation device which is inserted in said punch carrier drive means.

References Cited by the Examiner UNITED STATES PATENTS 1,437,935 12/1922 Gaess 10'-12.5 2,305,049 12/ 1942 Wilcox 1012.5 2,784,427 3/1957 Wright 10-12.5

FOREIGN PATENTS 948,667 9/ 1956 Germany.

CHARLES N. LANHAM, Primary Examiner.

G. P. CROSBY, Assistant Examiner. 

